Message buffer with improved escape sequence and automatic document marking
US4852045A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1988 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Sep 9, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/1284
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An improved message buffer for transferring data between two or more digital data devices is disclosed. A dual universal asynchronous receiver-transmitter (13) provides bidirectional data flow to two bidirectional ports (B and C) through two interface circuits (14 and 15). A peripheral interface adapter (16) and a third interface circuit (17) provide for sending data to an output port (A) in a serial or a parallel data format, and provides access to a real time clock (20), an electrically erasable programmable read only memory (41), a bank of switches (36), and a bank of display indicators (37). A read only memory (11) provides operating instructions to a control unit (10). The control unit (10) reads data and handshake signals from the two bidirectional ports (B and C), stores the data in a random access memory (12), reads the data from the memory (12) and sends it to the output port (A). The control unit (10) is responsive to a predetermined period of no data from the bidirectional ports (B and C) for automatically marking the beginning and end of a document. The control unit (10) is also responsive to a minimum and a maximum period of a break signal followed by a first predeterm…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.